Multiple conduit system for elevating contact material



April 6, 1954 c. H. THAYER 74,496

ONTACT MATERIAL MULTIPLE CONDUIT SYSTEM FOR ELEVATING C Filed Oct. 18,1950 2 Sheets-Sheet l 371NVENT0R. CLARENCE H THAYER My ATTORNEYS April6, 1954 c. H. THAYER 2,674,496 MULTIPLE CONDUIT SYSTEM FOR ELEVATINGCONTACT MATERIAL Filed Oct. 18, 1950 2 Sheets-Sheet 2 I INVENTOR.

%LARENCE H. THAYER i a MJAL'IVL A? ATTORNEYS Patented Apr. 6, 1954SYSTEM FOR ELEVAT- MULTIPLE GONDUIT ING 'CON TA CT MATERIAL Clarence H.Thayer, Wallingford, Pa., assignor to Sun Oil Company, Philadelphia,Pa., a corporation of New Jersey Application October 18, 1950; SerialNo. 190,728

14 Claims. 1

This invention relates to a system and apparatus for movingpneumatically granular or pelleted contact material or catalyst froma-lower receptacle, which receives the material in a continuous stream,upwardly into an upper recepl'n particular the invention is directed tothe method of and apparatus for regulating the ratio of gas, air orother fluid lifting medium to the contact material so that it can beconveyed from the lower receptacle to and through one or a plurality ofconveying conduits-to an upper chamber in a manner to reduce attritionof the material particles or pellets to a minimum.

It is well known in the art of catalytic operations, such as thecracking of heavier petrole fractions to gasoline and other hydrocarbonprocessing operations, to use a catalytic or contact material in acontinuous system. In such 1 continuous systems a conversion zone isoperated continuously to produce the desired product while a second zoneoperates continuously in regeneration. Most commercial moving catalystsystems have the-conversion zone and regeneration zone in superposedrelationship with the conversion zone usually above the regenerationzone so that the catalyst or contact material moves throughtheconversion zone to the regeneration zone by gravity and afterregeneration it is carried upwardly and returned to the conversion zoneto repeat the cycle of operation. To return the catalyst or contactmaterial from the lower regenerating zone to the upper conversion zonetwo well known means applicable to the transportation of granular solidsfrom one locus to another have been used, namely: by mechanicalconveyors and by pneumatic conveyors, in the latter of which air, steamor flue gas produced at the refinery is readily available as thepneumatic lifting medium.

It is necessary in systems employing conversion and regeneration zonesin superposed relationship to convey the catalyst or contact materialcontinuously upwardly to a height of several hundred feet, in order thatit can be delivered continuously by gravity to these zones and maintainthe desired volumes of the material therein to effect optimum operation.Conveying the material upwardly by a fluid medium requires a receptaclepostioned at a level below that of the lower reaction zone which isdesigned to effect the lifting or upward conveying operation. Thislowermost receptacle is generally known in'the art as an engager sincethe material is engaged therein by the lifting fluid to effect thelifting operation. A lift conduit has its lower'end exknown as thedisengager.

The maintenance of a constant and predetermined rate of flow of liftingfluid and catalyst through the lift is a desideratum which is essentialto satisfactory operation but is diflicult of achievement. The idealcondition is to so regulate the velocity of the lifting fluid that thecatalyst will be lifted with just sufiicient force to effect itsemergence from the top .of the lift, so that it will drop gently downinto the disengaging chamber. To the extent that a constant andpredetermined rate of fiow of lifting fluid and catalyst, with a forceregulated as specified, is approached, attrition is greatly reduced.

But this ideal condition, it is believed, has not been reached inpractical operation before my invention. Thus, thereis a tendency forthe lifting fluidto channel a rapid path along the axial region of thelift with relatively slow flow of catalyst along the lift Wall and evensome fall of catalyst from this peripheral region laterally and downwardagainst the catalyst being projected along the axial region. Thisoperation not only produces a departure from the ideal constant rate offlow of the catalyst from the engager to the disengager, but it givesrise to excessive-frictional contact between the particles ofthecatalyst with resultant excessive attrition.

constantvelocity of flow of lifting fluid and catalystis to bemaintained), is necessarily reduced, thus increasing the velocity offlow of lifting fluid.

On theother hand conditions may arise causing more or less clogging ofthe lift with such resistance to upflow of the catalyst that the forceof the lifting fluid is not adequate to carry the catalyst to the topofthe lift. In this operation it is obvious that a back pressure will becreated against the inflowing. lifting fluid with resultant decrease inthe velocity of flow of the lifting fluid.

'Either departure from the desired normal tends to aggravate .thecondition,.causing such a departure with resultant further departurefrom the desired normal of-rate of flow of the lifting fluid andquantityof catalyst supplied to the lift conduit.

I have found that the conditions causing these irregularities, andespecially the tendency of the lifting fluid to channel a separate pathalong the lifts axis, is greatly reduced by substitution, for the usualsingle lift conduit of wide diameter, a multiplicity of lift conduits ofcomparatively small diameter, all leading from the engager to one commondisengager. This substitution is especially effective if the catalyst isfed to the lower ends of the respective lifts by channels separated eachfrom the other. Such an arrangement, while it ameliorates certain of thefactors that in actual operation effect a departure from the desirednormal rate of flow of lifting fluid and catalyst, do not alone solvethe problem. Indeed there still remains the liability of the catalyst tomore or less clog the lift with resultant diminution of rate of flow ofthe lifting fluid and catalyst as above explained.

In the event of a departure from the desired constancy of flow oflifting fluid and catalyst, restoration of that constant flow iseffected in the process embodying my invention, as hereafter described.Let it be assumed that conditions arise tending to obstruct the flow ofcatalyst through the lift and thus creating a back pressure operation toreduce the flow of lifting fluid. When this condition arises means areprovided to automatically allow a more free flow of lifting fluid,causing it to overcome this back pressure and restore to normal. At thesame time the volume of catalyst at or below the lower or admission endof the lift, that is, the thickness of the zone of catalyst againstwhich the lifting fluid is projected, decreases; this operationcontinuing until the volume of catalyst in the lift is reduced to normaldepth and consequent restoration of constancy of flow of lifting fluidand catalyst through the lift.

On the other hand, if the flow of lifting fluid through the lift becomestoo free and rapid, thus reducing the normal difference in pressurebetween the upper and lower ends of the catalyst, means are provided toautomatically throttle the inflow of lifting fluid; and at the same timethe volume of catalyst acted upon by the lifting fluid increases, thisoperation continuing until the volume of catalyst in the lift isincreased to normal with constant restoration of constanc of flow oflifting fluid and catalyst through the lift conduit.

It should be understood that while I have described the operation of theprocess on the assumption of the existence of a departure from normalrate or velocity of lifting fluid and catalyst through the lift, in thepracticed operation of the process such an abnormal condition cannot toany pronounced degree usually arise, since the process functions asdescribed upon such slight departures from the desired normal that thedesideratum of maintenance of the desired constancy of flow of liftingfluid and catalyst is substantially attained.

It should also be understood that while the substitution of a pluralitof small diameter lift conduits for a single lift conduit of largediameter is of substantial importance, the described features ofgoverning the volume or rate of feed of the lifting fluid and ofgoverning the thickness of the zone of catalyst that is in the path ofthe lifting fluid, are operative whether a single lift or a plurality ormultiplicity of lift conduits are provided. In the latter applicationthe devices es" sential to the described operation should be applied toeach individual lift conduit.

While the practice of the process is not limited to the employment ofparticular control or regulating devices a construction and arrangementadapted to automatically perform the aforesaid process is hereinafterdescribed, such construction and arrangement being illustrated in theaccompanying drawings in which:

Figure 1 is a diagrammatic view of a system utilizing a continuouslymoving body of contact material.

Figure 2 is a view generally in vertical section showing the details ofa lift conduit.

Figure 3 is an elevational view showing the system for controlling thesupply of lifting medium and also the system for adjusting the supply ofcontact material to the lift conduit.

Figure 4 is a sectional view taken on the line 44 of Figure 3.

Referring to Figure 1, if! indicates the engager which receives catalystor contact material through line H from a reaction zone such as aregenerator l2 positioned below an upper reaction zone 13 which is incommunication with zone i2 through line I l and which receives contactmaterial continuously through line Hi from a disengaging zone i5. Meansfor conveying the contact material from the engager 10 to the disengagerI5 is shown generally at l6. Separating means such as a cycloneseparator l! is in communication with the disengager 15 through line if!and fines are removed by the separator through line i9 while the liftingmedium is removed from the separator i1 through line 20. Figure 1 doesnot show any details of the present invention and is provided only toshow the general arrangement of a continuous system wherein catalyst orcontact material is utilized in a continuously moving mass.

Referring to Figure 2 which shows details of the lift conduitarrangement of the present invention associated with the engager l0 andalthough only one such conduit arrangement is shown it will beunderstood that a plurality are contemplated in the specific adaptationof the invention. The lift conduit is indicated generally at 2i while 22indicates an outer conduit or sleeve secured about the lower portion ofthe lift conduit and enclosing the inlet end 23 of the lift conduit. Thesleeve 22 will be maintained fixed relative to the engager l0 and may besecured thereto as by welding. The upper open end of the sleeve 22 isprovided with lugs 24 in order to maintain the sleeve rigid with respectto the lift conduit 2| and the lower portion of the sleeve 22 extendsthrough the lower end of the engager I0. A partition plate 25 is securedwithin the sleeve 22 at a point a short distance below the inlet end 23of the lift conduit and provides an upper chamber C for contact materialand a lower chamber F for lifting fluid medium. It will be understoodthat as the contact material is returned to the engager [0 that theengager will be maintained substantially full of contact material andalso that the space C between the lift conduit 2! and sleeve 22 willalso be maintained constantly filled. Below the plate 25 is provided aguide ring 25 providing a space 2'! with the plate 25 and a liftingfluid supply conduit 28 is in communication with the space 21 for thesupply of lifting nedium thereto. The guide ring 28 is apertured so thatthe lifting medium from the conduit 28 is directed downwardly throughthe apertu es and then upwardly through the nozzle 29 to the inlet 23 ofthe air lift conduit.

aemnee Thenozzle' n is positioned in apertures'rifl and wardly throughthe aperture I3| to the lower end of the nozzle 29 and also a smallamount of air may pass through the aperture 30 toprevent any finesexisting in the .contact material from entering the fluid section F.Provision is made for-the nozzle 29 to be adjustable toward and from theinlet 23 of the lift conduitin order to adjust the distance therebetweenand vary the contact material zone A between the inlet end 23 and theupper end of nozzle 29. To this end a shaft 32 is provided having itsupper end as in a piston P which is movable in cylinder 35 and themovement of the nozzle is in accordance with the position of the :pistonPin the cylinder 35 which is regulated by the supply of acontrol fluidto the cylinder through lines 36 and 31 as will be described more fullyin connection with Figure'3.

The volume and velocity of the lifting fluid discharged throughnozzle29, the differential pressure between theengager and the disengager, andthe amount of catalyst that is propelled through the lift conduit in agiven time, should be accurately controlled in order that there shouldbean accurate correspondence between the rate offiow of the catalystintothe engager and-the rate of conveyance .of the catalyst from theengager to the :disengager. Under some conditions of operation it ispossible to so control the rate of flow into the engager and also thedifferential pressure between the engager and 'disengager that they may:be maintained in substantially exact correspondence with each other.However, under some conditions of operation neither the rate of flow :ofthe catalyst into the engager nor the differential pressure'between theengager and disengager may be constant, and it is then clear that, withafixed distance between thedischarge end of the nozzle ZQ-and liftconduit, and also by so controlling the supply of the incoming liftinggas, that the rate of flow ofthe catalyst to the engager and itsdischarge therefrom to the disengager will always be in *balance, whileatthe-same time the level of catalyst in'the engager lwill--remain-constant. This-figure in addition shows a-system for con"trolling the supply of liftingfluid to the inlet of "the lift conduitand also anarrangement for controlling the actuation of the piston Pwhich in turn controls the distance between the inlet .end 23 of thelift conduit and the upper end of nozz1e29 and hencethe volume ofcontact-mafte'rial in zone A. In order to adjust the position of thenozzle 129jpressure from thelift conduit "1| is transmitted 'by line Mot-ma -remote' control pressure transmitter which is located inthe plantin close proximity to the lift conduit; air from the plant, which istermed instrument air and used for the control of various instruments,is also supplied to the pressure trans,- mitter 4| by line 42 and theinstrument air from the pressure transmitter 4| is directed byline 3 toa pressure controller 44 which is located tion of the piston P and thusadjust the position of nozzle 29 with respect to inlet 23 of the liftconduit. In order to control the supply'oi the lifting medium to thecontact material zone A an orifice plate 0 is positioned in the supplyconduit 28 between flanges 5l.-52 and flow lines 53-54 leave from aboveand below respectively of the orifice plate to a manometer M which isenclosed in a how transmitting cylinder.55 located in the plant.Instrument air is supplied to the flow transmitting cylinder 55 throughlines 56 and 51 and in accordance with the differential pressure acrossthe orifice plates air will' be transmitted therefrom by line 58 to aflow recording cylinder 59 positioned in the control room and from whichair will be directed back to the plant by line .60 for operation of adiaphragm valve 6| to control the supply of air through the conduit 28to the contact material zone A.

The remote control pressure transmitter 41 the pressure controller 44,the piston controller 45, the flow transmitting cylinder 55 and .theflow recording cylinder 59 are instruments well known in the art andreadily available on the market and hence no detailed description ofthese elements is considered necessary for an understanding of theinvention.

Figure 4 shows one pattern for arranging a plurality of lift conduits 2iand outer catalyst and air supply sleeves 22 within the engager [0.

It will be understood that the volume of contact material in compartment0 of the sleeve 22 is sufficient to provide a continuous supply ofmaterial to the zone Abelow the inlet end '23 of the lift conduit and isalso suflicient to prevent migration of the lifting medium from one airlift conduit to another when a plurality are utilized. The rate ofsupply of lifting medium from onevconduit 23 will determine the velocityof the contact material upwardly through the lift conduit and the rateof supply of lifting fiuid and the rate of supply of contact material tozone A will determine the differential pressure between the upper andlower portions of the lift conduit and provide a control system whereinattrition of the contact material isreduced to a minimum.

It is customary in elevating contact material from an engager to adisengager to make provision for exerting pressure on the bed ofcontactmaterial in orclerto deliver it to the inlet of the terial is admittedat a point adjacent the top of the engager, the material acquires anangle of repose and it is advantageous to admit the pressure medium at acommon level within the body of contact material in order to exert equaldownwar pressure.

I claim:

1. Method of elevating contact material through a plurality of confinedpassageways each having an inlet end in communication with a lowervessel and an outlet end in communication with an upper vessel whichcomprises the steps of maintaining a body of the material within thelower vessel, supplying contact material to independent contact materialzones adjacent the inlet end of each passageway, simultaneously.supplying a stream of lifting fluid to the bottom of each of said zonesto direct the material from the zone upwardly into and through thepassageways to the upper vessel and controlling the rate of supplyingthe contact material to said zones in accordance with the pressureconditions existing at selected loci in the passageways.

2. In the conveyance of solid particles from a lower vessel to an uppervessel through a conduit in which particles of solid material arecontinuously supplied to the lower vessel and in which a zone of suchmaterial is maintained adjacent the lower inlet end of the conduit andin which a stream of conveying i-luid is directed to the lower end ofsaid zone of material, the proces of maintaining a substantiallyconstant rate and velocity of flow of material into said conduit byvarying the depth of material within said zone in accordance with anyvariation of pressure within said conduit.

3. In the conveyance of solid particles from a lower vessel to an uppervessel through a conduit, in which particles of solid material arecontinuously supplied to the lower vessel and in which a restricted zoneof such material is maintained adjacent the lower inlet end of theconduit and in which a stream of lifting fluid under pressure isdirected upward. against said zone of material, the process ofmaintaining a substan- 1F tially predetermined rate and velocity of flowof material through said conduit which comprises, upon occurrence of anyvariation of such rate and velocity of flow and consequent rise or fallof fluid pressure in said conduit, controlling by such pressure thevolume of material against which said stream of lifting fluid isdirected to thereby change the rate of flow of material into saidconduit and thus re-establish the predetermined rate and velocity offiow of material through said conduit.

4. Method of elevating contact material through a confined passagewayhaving an inlet end in communication with a lower vessel and an outletend in communication with an upper vessel, which comprises the steps ofmaintaining a zone of contact material adjacent the inlet end of saidpassageway, supplying a stream of lifting fluid to the bottom of saidzone at a predetermined rate of flow to direct the material from thezone upwardly into and through the passageway to the upper vessel, andvarying the depth of the zone of contact material by varying thedistance between the inlet end of said passageway and the oint ofdischarge of said stream of lifting fluid into said zone in accordancewith the pressure existing at a selected locus in said passage- 5. Inthe conveyance of solid particles from one vessel to another through aconduit, in which particles of solid material are continuously suppliedto the first vessel and in which a restricted zone of such material ismaintained adjacent the inlet end of the conduit and in which a streamof conveying fluid under pressure is directed through a supply conduitand thence through a nozzle against said material and toward the inletend or the conduit, the process of regulating the rate of conveyance ofthe material from said zone to the conveying conduit by moving saidnozzle toward and from the inlet to said conveying conduit and varyingthe position of said nozzle in accordance with the pressure existing ata selected locus in said conveying conduit.

6. Method of elevating contact material through a confined passagewayhaving an inlet end in communication with a lower vessel and an outletend in communication with an upper vessel, which comprises the steps ofmaintaining a zone of contact material adjacent the inlet end of saidpassageway, supplying through a fluid supply conduit a stream of liftingfluid to the bottom of said zone to direct the material from the sameupwardly into said passageway, maintaining a predetermined rate ofsupply of lifting fluid to said zone by measuring th pressuredifierential ahead of and beyond a locus in said supply conduit andthrottling ahead of said locus the flow of fluid through said conduit inaccordance with said pressure differential.

'1. Method of elevating contact material through a confined passagewayhaving an inlet end communicating with a lower vessel and an outlet endcommunicating with an upper vessel, which comprises maintaining a zoneof contact material in said lower vessel adjacent the inlet end of saidpassageway, flowing through a supply conduit a stream of conveying fiuidand directing it upward into said zone of contact material to force thematerial in said zone up into and through said passageway, increasing ordecreasing the freedom of flow of the conveying fluid through saidconduit to said zone in accordance with the rise or fall of thedifferences in pressure between the upper and lower ends of saidpassageway, and simultaneously varying the volume of catalyst againstwhich the conveying fluid is projected to force the catalyst into suchpassageway, thereby maintaining a substantially constant rate of flow ofconveying fluid and catalyst through said passageway.

8. Method of elevating contact material through a confined passagewayhaving an inlet end communicating with a lower vessel and an outlet endcommunicating with an upper vessel, which comprises maintaining a zoneof contact material in said lower vessel adjacent the inlet end of saidpassageway, flowing through a supply conduit a stream of conveying fluidand directing it upward into said zone of contact material to force thematerial in said zone up into and through said passageway, so varyingthe supply of conveying fluid as to maintain a substantially constantpressure of conveying fluid so directed upward into said zonenotwithstanding any variation in pressure in, and rate of flow ofcontact material through, said passageway, and varying the rate at whichcontact material is forced from said zone into said passageway inaccordance with variation in pressure existing at a selected locus insaid passageway.

9. Apparatus :for elevating contact material from a lower chambercontaining a body of the material to an upper chamber which comprises anelevating conduit having its lower inlet end chamber.

11. Apparatus as in claim 9 further characterzed by driving means forsaid nozzle and control means between the elevating conduit and portionof the elevating conduit.

12. Apparatus as in claim 9 further characterupper'portion of theelevating conduit and other control means connected with the liftingfluid disposed below the lower end of the corresponding elevatingconduit providing with the inlet end of the conduits a space for contactmaterial, a lifting fluid nozzle communicating through the lower end ofeach sleeve with each space for and its upper outlet end extending intothe upper chamber, a sleeve positioned about the lower portion of eachconduit, each sleeve having its References Cited in the file of thispatent UNITED STATES PATENTS Number Name Date 528,417 Duckham Oct. 30,1894 1,364,532 Von Porat Jan. 4, 1921 1,390,974 Von Porat Sept. 13, 19211,549,285 Baker Aug. 11, 1925 2,433,726 Angell Dec. 30, 1947 2,463,623HuiT Marc 8, 1949 2,487,961 Angell Nov. 15, 1949 2,541,077 Lefier Feb.13, 1951 2,561,771 Ardern July 24, 1951

